Outlander for the Super Nintendo.
When a new high score is achieved, enter SMEGHEAD as the name. The programmer(s) apparently thought the curse might get censored and obfuscated it by subtracting $41 from each byte, unlike STARBUG1 (see next section) which is stored in plain ASCII. On the high score screen displayed afterwards, the name is changed to CHEATED, and 7E07E9 is set to 01. After that, the cheat gets broken: the game jumps back to the Mindscape logo after the high score screen, where memory is cleared, wiping out the bit setting.
Use Pro Action Replay (PAR) code 7E07E901 on bootup to fix the cheat. The title screen will be transparent, and 7E04E9 is set to 01. During gameplay, in side-scrolling action areas press Start on controller 2 to instantly restore health to full.
Enter STARBUG1 on the high score screen to view the ending credits.